The mother-of-two and her fiancé, Eric Johnson, opted for a fun night without costumes on Halloween, celebrating instead with the blond beauty's sister, Ashlee Simpson and her BFF, CaCee Cobb.

Ashlee's boyfriend, Evan Ross, as well as Cobb's husband, Donald Faison, joined the group for a triple date at Mastro's Steakhouse in Los Angeles.

The fashion mogul looked stunning in a tight black dress that flaunted her curves to perfection, while Ashlee looked chic in a white blouse with black polka dots and black slacks. Both sisters were holding hands with their beaus.

The 33-year-old singer recently opened up in a guest blog post on Parents.com about her pregnancy weight gain, writing candidly about body image and what she wants her 17-month-old daughter, Maxwell, and 4-month-old son, Ace, to learn from her.

"My pregnancies (especially my first with Maxwell) were well documented and my struggles with my weight and body image have played out in front of the world," Simpson wrote. "As hard as that has been, the hardest part is to realize that with all the hurtful and harsh criticism from others, I have been the hardest on myself."

Jessica and her fiancé have yet to reveal their upcoming wedding date, but rumors are swirling the couple will tie the knot in spring 2014.